The norbar model 5 torque wrench is highly accurate and convenient with interchangeable 14 in hexagon bits iso 11731988 form c drive bits has an accuracy of 3 of reading which exceeds all torque wrench standards all wrenches come with a traceable calibration certificate that complies to iso90002000 standards the model 5 is non length dependent and remains accurate regardless of hand position supplied in a storage case that allows space for the storage of additional drive bits and optional stepl